<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title>图像适配</title>
	</head>
	<body>
		<picture>
			<source media="(min-width:1024px)" srcset="img/cute.png">   
			<source media="(min-width:512px)" srcset="img/girl.png"> 
			<img src="img/tree.png"  alt="树" style="width: auto;">
		</picture>
	</body>
</html>
